Geologic formations are used for many applications such as hydrocarbon production, geothermal production, and carbon dioxide sequestration. Typically, boreholes are drilled into the formations to provide access to them. Various downhole tools may be conveyed in the boreholes in order to characterize the formations. Characterization of the formations and the fluids within provides valuable information related to the intended use of the formation so that drilling and production resources can be used efficiently.
Several types of downhole tools use a semiconductor photodetector to detect and measure an amount of photons for various characterization processes such as spectroscopy for sample identification or chemical analysis. However, borehole temperatures can be very high, up to 200° C. or more, and degrade the performance of these photodetectors especially for detecting photons in the near-infrared range of wavelengths. Hence, improvements in semiconductor photodetectors that are required to operate accurately at high downhole temperatures would be well received in the drilling and geophysical exploration industries.